Vehicle operators frequently engage in secondary tasks, which can result in what is typically referred to as distracted driving. In recent surveys, about two-thirds of all drivers reported using a cell phone while driving. And a study by the Virginia Tech Transportation Institute revealed that texting while driving increases the risk of being involved in a critical incident by 23 times. As an example of the dangers of distracted driving, 13.8 percent of fatal traffic crashes from 2011-2013 in the state of Missouri involved at least one distracted driver.
Mobile road crews often use signs mounted on vehicles to warn motorists of operations ahead and to divert vehicles before they reach the work zones. Vehicle-mounted signs and the like use high-intensity rotating, flashing, oscillating, or strobe lights. Unfortunately, the effectiveness of a warning sign is greatly diminished by distracted driving. In other words, a motorist must notice a warning sign for it to be effective.